I've also looked at the existence of CCD memory, but it doesn't seem to be a thing anymore. I didn't find any such modern chips.
-not quite the same but similarly novel.
I think they can be used with analog signals too. After all, they are (I suppose) just a chain of transistors holding charge, like in a CCD. It is just the most efficient implementation, since doing it with logic gates will bring more overhead. EDIT: maybe not, it seems at least some of these chips have digital input/output stages. Maybe it could work if you put a very fast 8-bit ADC in front of the delay line, and used 8 delay lines, one for each bit? :)
Anyway, I have totally zero experience with these chips.
But I can imagine you clock-in the signal using a fast clock (maybe the internal clock), and then you clock-out the signal using a slow clock (slow enough for a subsequent ADC chip).
Also, perhaps you can put a bunch of these combinations in parallel to increase bandwidth, or to increase sample depth.
There seems to be no way to debug this stuff unless you are a big company that can pay large sums of money.
If you're designing a board, not being able to look at its signals is a major limitation. Is something wrong with the transmitter, receiver, cable, connector, pcb, firmware, driver? Who knows! It doesn't work, and that's all you're going to get. Have fun randomly tweaking stuff in the hope that it is magically going to work.
Indeed. Even if you have an instrument, and the skill to operate it and produced a meaningful result that reveals some problem, that doesn't spell out a solution. It may help, but high frequency is subtle.
There can even just be manufacturing defects the FR4 weave that mess up SI that you might want to check for as a QA step on the assembly line. For hi volume that gets slow or expensive
Yes, but: You don’t need a general purpose realtime high bandwidth scope for verifying signal integrity.
You can use an equivalent time sampling scope (~10ksps to 100ksps) to measure the eye diagram and ensure that the received eye matches the mask specified by the spec.